Improved antenna with lateral directional beam and reverse space rejection

Abstract

The present application provides an improved antenna with lateral directional beam and reverse space rejection, wherein the planar radiation source of the planar antenna generates a reactive field based on self-coupling, and compared with the planar antenna with directional radiation characteristics, the present application forms a conductive surface in the direction of the reactive field, which meets certain size and area requirements, and meets certain distance requirements with the planar antenna, so that the electromagnetic induction of the reactive field on one side of the planar radiation source can be blocked by the conductive surface, and the blocked reactive field energy can be fed back to the planar antenna through the conductive surface in a low-consumption or even no-consumption state, so that the electromagnetic radiation generated by electromagnetic induction on this side of the improved antenna can be blocked, and the radiation pattern presents a low back lobe radiation characteristic, and the improved antenna on the other side has a strengthened radiation beam.

Description

Technical Field

[0001] This invention relates to the field of directional microwave detection based on the Doppler effect principle, and particularly to an improved antenna for lateral directional beamforming and reverse space rejection of a planar antenna that inherently possesses directional radiation characteristics. Background Technology

[0002] With the development of IoT technology, artificial intelligence, smart homes, and smart security technologies have increasingly higher demands for the accuracy of environmental detection, especially the detection of human presence, movement, and subtle motion characteristics. Only by obtaining sufficiently stable detection results can accurate judgments be provided for smart terminal devices. Among these technologies, directional microwave detection based on the Doppler effect principle serves as a crucial hub connecting people and objects, and between objects themselves. It possesses unique advantages in behavior and presence detection technologies. Without infringing on human privacy, it emits a microwave beam and receives the reflected echo formed by the beam's reflection from a corresponding object. Subsequently, based on the Doppler effect principle, a Doppler intermediate frequency (IF) signal corresponding to the frequency difference between the microwave beam and the reflected echo is generated through frequency mixing and detection. This IF signal provides feedback on the movement of the corresponding object. When applied to the detection of human activity, including breathing and heartbeat, it enables intelligent interconnection between people and objects. While possessing broad application prospects, existing directional microwave detection modules suffer from a lack of effective means to constrain electromagnetic radiation in non-directional radiation directions. This is primarily reflected in the scarcity of means to constrain electromagnetic radiation in the backward direction of directional radiation. As a result, a significant radiation space remains in the backward direction of the directional radiation direction, leading to a mismatch between the actual detection space of the existing microwave detection module and the directional target detection space. This results in environmental interference in the reverse space of the directional target detection space, including motion interference, electromagnetic interference, and self-excited interference caused by multipath reflection in environments with multiple electromagnetic reflectors. Consequently, existing directional microwave detection modules exhibit poor detection accuracy and / or poor anti-interference performance.

[0003] Specifically, existing directional microwave detection modules, based on directional detection requirements, generally use planar antennas with inherent directional radiation characteristics as their transmitting and / or receiving antennas, referencing... Figure 1 As shown, a structure of a conventional planar antenna 10 and its corresponding radiation pattern and S11 curve are schematically illustrated. The planar antenna 10 includes a reference ground plane 11 and a planar radiation source 12, both disposed in the form of planar metal layers and spaced apart in a parallel manner. To form the parallel spaced structure of the reference ground plane 11 and the planar radiation source 12, the reference ground plane 11 and the planar radiation source 12 are typically mounted on two opposite surfaces of the same circuit board (e.g., ...). Figure 1 As shown in the figure, the reference ground 11 and the planar radiation source 12, which are respectively disposed in the form of a planar metal layer, are respectively supported on two circuit boards, and the reference ground 11 and the planar radiation source 12 are spaced apart in a parallel state based on the fixation between the two circuit boards. The planar radiation source 12 is disposed at a position off its physical center point and is fed, including but not limited to at least one of the following feeding structures: probe feeding structure, microstrip feeding structure, side feeding structure, and corner feeding structure. The radiation pattern of the planar radiation source 12 in the fed state is shown in the figure. The planar antenna 10 exhibits directional radiation characteristics with the direction from the reference ground 11 to the planar radiation source 12 as the directional radiation direction, and still has a large radiation gain in the backward direction of the directional radiation direction.

[0004] In other words, existing planar antennas 10 are widely used in directional microwave detection modules with directional detection requirements due to their inherent directional radiation characteristics. However, existing planar antennas 10 still have a large radiation gain in the backward direction of the directional radiation direction, resulting in a large radiation space in the microwave detection module in the backward direction of the directional radiation direction. This leads to environmental interference in the reverse space of the directional target detection space, including motion interference, electromagnetic interference, and self-excited interference caused by multipath reflection in environments with multiple electromagnetic reflectors. This results in poor detection accuracy and / or poor anti-interference performance of existing directional microwave detection modules. Therefore, based on the understanding that existing planar antennas 10 inherently possess directional radiation characteristics, those skilled in the art are accustomed to aiming to constrain the radiation gain of the planar antenna 10 in the backward direction of the directional radiation direction as the improvement goal / idea in improved antennas based on the existing planar antenna 10. Based on corresponding structural and / or circuit designs, they constrain the radiation gain of the planar radiation source 12 towards the reference ground 11, but the actual improvement effect is not ideal. Summary of the Invention

[0005] One object of the present invention is to provide an improved planar antenna with lateral directional beamforming and reverse space rejection, wherein, compared with a conventional planar antenna with directional radiation characteristics, the improved antenna has a directional radiation direction that is laterally deviated from the original directional radiation direction, and has electromagnetic radiation rejection characteristics in the reverse space of the lateral directional radiation direction. Accordingly, the improved antenna has good applicability and anti-interference performance in the field of directional microwave detection.

[0006] Another object of the present invention is to provide an improved antenna for lateral directional beamforming and reverse space rejection of a planar antenna, wherein the improved antenna further includes an electric field isolator based on the structure of the planar antenna, wherein based on the structure of the electric field isolator and its positional relationship with the planar antenna, the reactive field generated by the planar antenna based on its own coupling can be laterally directionally enhanced, thereby making the improved antenna exhibit lateral directional radiation characteristics and having a beamformed by beamforming in the lateral directional radiation direction.

[0007] Another object of the present invention is to provide an improved planar antenna with lateral directional beamforming and reverse space rejection, wherein the improved antenna has a beamformed by beamforming in the lateral directional radiation direction, and thus exhibits a high front-to-back ratio characteristic with a large lateral directional gain, thereby helping to ensure the detection sensitivity of the improved antenna in the lateral directional radiation direction.

[0008] Another object of the present invention is to provide an improved antenna for lateral directional beamforming and reverse space rejection of a planar antenna, wherein, based on the structure of the electric field isolator and its positional relationship with the planar antenna, the electromagnetic induction of the planar antenna in the reverse space by the reactive field generated by its own coupling in the lateral directional radiation direction can be blocked. Correspondingly, the improved antenna can block the electromagnetic radiation generated by electromagnetic induction in the reverse space, thus exhibiting a low back lobe radiation characteristic in the radiation pattern. Therefore, it is beneficial to achieve the rejection of electromagnetic radiation in the reverse space by the improved antenna based on the reciprocity of the antenna's transmit and receive characteristics.

[0009] Another object of the present invention is to provide an improved antenna for lateral directional beamforming and reverse space rejection of a planar antenna, wherein, based on the structure of the electric field isolator and its positional relationship with the planar antenna, the electromagnetic induction of the planar antenna's reactive field generated by its own coupling in the reverse space in the lateral directional radiation direction can be blocked, and the blocked reactive field energy can be fed back to the planar antenna through the electric field isolator with low or even no loss, thereby enabling the reactive field of the planar antenna to be laterally directionally constrained, thus achieving beamforming enhancement of the improved antenna's radiation beam in the lateral directional radiation direction.

[0010] Another object of the present invention is to provide an improved antenna for lateral directional beamforming and reverse space rejection of a planar antenna, wherein the electric field isolator has a lateral beamforming surface formed in a conductive material, wherein, based on the structure of the electric field isolator and its positional relationship with the planar antenna, the lateral beamforming surface meets certain size requirements along the direction of the reactive field generated by the planar antenna based on its own coupling and meets certain distance requirements between the planar antenna and the planar antenna, so that the electromagnetic induction of the reactive field of the planar antenna in reverse space can be blocked by the lateral beamforming surface, and the blocked reactive field energy can be fed back to the planar antenna through the lateral beamforming surface with low or even no loss. Correspondingly, the electromagnetic radiation generated by electromagnetic induction in the reverse space in the lateral directional radiation direction of the improved antenna can be blocked, resulting in a low back lobe radiation characteristic in the radiation pattern, and the improved antenna has a beamformed by beamforming in the lateral directional radiation direction.

[0011] Another objective of this invention is to provide an improved antenna for lateral directional beamforming and reverse space rejection of a planar antenna. In this improved antenna, the lateral beamforming surface meets certain dimensional requirements along the direction of the reactive field generated by the planar antenna's self-coupling and a certain distance requirement between the planar antenna and the antenna. The improved antenna exhibits low backlobe radiation characteristics in its radiation pattern and can achieve reverse space rejection based on the antenna's reciprocal transmit / receive characteristics. In other words, the design of the lateral beamforming surface that meets the aforementioned requirements can simultaneously achieve beamforming enhancement in the lateral directional direction and rejection of electromagnetic radiation in the reverse space.

[0012] Another object of the present invention is to provide an improved antenna for lateral directional beamforming and reverse space rejection of a planar antenna, wherein the electric field isolator has a reverse rejection surface formed in a conductive material, wherein, based on the structure of the electric field isolator and its positional relationship with the planar antenna, the reverse rejection surface meets certain size requirements along the direction of the reactive field generated by the planar antenna based on its own coupling, and meets certain distance requirements between the planar antenna and the planar antenna. This ensures that electromagnetic radiation from reverse space cannot be received by the planar antenna in the form of electromagnetic waves through diffraction, nor can it affect the planar antenna based on the coupling between the reverse rejection surface and the planar antenna when received by the reverse rejection surface. Correspondingly, the reception rejection characteristics of the improved antenna for electromagnetic radiation from reverse space can be further enhanced based on the design of the reverse rejection surface satisfying the aforementioned requirements.

[0013] Another object of the present invention is to provide an improved antenna for lateral directional beamforming and reverse space rejection of a planar antenna, wherein the reactive field generated by the planar antenna based on its own coupling is an inductive field and does not radiate energy outward. That is, when the lateral beamforming surface is located in the reactive field generated by the planar antenna based on its own coupling, the lateral beamforming surface does not exhibit reflection behavior during the lateral directional radiation of the improved antenna based on electromagnetic induction. However, when the improved antenna is used as a receiving antenna independently or simultaneously, the reflection capability of the lateral beamforming surface of electromagnetic radiation in the lateral directional space is not limited. The electromagnetic radiation in the lateral directional space can still be reflected by the lateral beamforming surface and received by the planar antenna, thereby improving the receiving sensitivity of the improved antenna when used as a receiving antenna.

[0014] Another object of the present invention is to provide an improved antenna for lateral directional beamforming and reverse spatial rejection of a planar antenna, wherein the shape of the electric field isolator and / or its positional relationship with the planar antenna is adjustable so that, based on the requirement that the size of the lateral beamforming surface relative to the reactive field generated by the planar antenna based on its own coupling along the reactive field direction and the distance between the lateral beamforming surface and the planar antenna meet the corresponding requirements, the beam deflection angle and bandwidth of the improved antenna can be adjusted based on the shape of the electric field isolator and / or the positional relationship with the planar antenna, thereby enabling the improved antenna to meet different detection requirements and have better applicability.

[0015] According to one aspect of the invention, the invention provides an improved antenna for lateral directional beamforming and reverse space denial of a planar antenna, said improved antenna comprising:

[0016] At least one planar antenna, the planar antenna comprising a reference ground plane disposed in the form of planar metal layers and spaced apart in a parallel manner, and a planar radiation source, wherein the planar radiation source is positioned off-center from its physical center point and fed by a feed signal, corresponding to the planar antenna being able to form an initial polarization and have a polarization direction in the fed state; and

[0017] An electric field isolator, wherein the electric field isolator is disposed of with a conductive material and has a lateral focusing surface, a three-dimensional coordinate system with the physical center point of the planar radiation source as the origin O, and an X-axis and a Y-axis of the three-dimensional coordinate system established on the planar radiation source along the polarization direction of the planar antenna, the Z-axis of the three-dimensional coordinate system being perpendicular to the planar radiation source, wherein a first sphere is defined with the origin O of the three-dimensional coordinate system as the center and a first radius R1 as the radius, a second sphere is defined with the origin O of the three-dimensional coordinate system as the center and a second radius R2 greater than R1 as the radius, and a first cone is defined with the origin O of the three-dimensional coordinate system as the vertex and the negative Y-axis as the axis, wherein the apex angle of the first cone in the XOY plane is... θ1 is defined as the space jointly defined by the first sphere, the second sphere, and the inner surface of the first cone as the first space. The lateral beam-gathering surface has a first cross-section intercepted by the first space. When the first cone has the first cross-section as its base, the base can independently block a conical beam with an angle of 46° inside the first cone, with the origin O of the three-dimensional coordinate system as the source point. The values ​​of R1, R2, and θ1 are set within the range of λ / 8≤R1<R2<3λ / 4 and θ1≥120°. λ is a wavelength parameter corresponding to the frequency of the feed signal connected to the planar radiation source. This makes the improved antenna exhibit lateral directional radiation characteristics in the radiation pattern, where the lateral direction is the direction corresponding to the positive Y-axis of the three-dimensional coordinate system.

[0018] In one embodiment, the planar antenna is configured to be fed by a probe-feed structure, having at least one feed point corresponding to the planar radiation source and a feed signal connected to the feed point, wherein the feed point is offset from the physical center point of the planar radiation source.

[0019] In one embodiment, the planar radiation source has one and only one feed point, corresponding to the state in which the planar radiation source is fed by a corresponding feed signal at the feed point, and the polarization direction of the planar antenna is the direction of the line connecting the feed point of the planar radiation source to the physical center point of the planar radiation source.

[0020] In one embodiment, the planar radiation source has two feed points and is fed differentially by feeding a feed signal with a phase difference to the two feed points. Corresponding to the state in which the planar radiation source is fed, the polarization direction of the planar antenna is a direction parallel to the line connecting the physical center point of the planar radiation source and the two feed points.

[0021] In one embodiment, the planar radiation source has two feed points and is fed with a feed signal of the same phase at both feed points. Corresponding to the state in which the planar radiation source is fed, the polarization direction of the planar antenna is the direction of the line connecting the midpoint of the line segment connecting the two feed points to the physical center point of the planar radiation source.

[0022] In one embodiment, the planar radiation source is configured to be fed by a microstrip feeding structure, with the planar radiation source being fed via at least one microstrip line connected thereto.

[0023] In one embodiment, the planar radiation source is fed from a single feed location, corresponding to the planar radiation source being fed through a single microstrip line, wherein in the state where the planar radiation source is fed, the polarization direction of the planar antenna is the direction of the line connecting the position of the planar radiation source connected to the microstrip line to the physical center point of the planar radiation source.

[0024] In one embodiment, the planar radiation source is configured to be fed by a side-feed structure, with the planar radiation source being fed via at least one side feed line coupled thereto.

[0025] In one embodiment, the planar radiating source is fed at a single feed location, corresponding to the planar radiating source being fed via a single side feed line coupled thereto, wherein in the state where the planar radiating source is fed, the polarization direction of the planar antenna is the direction of the line connecting the center position of the side feed line to the physical center point of the planar radiating source.

[0026] In one embodiment, the planar radiation source is recessed in the non-polarized direction so that the strength of the reactive field generated by the planar radiation source based on its own coupling can be increased, thereby increasing the radiation gain of the improved antenna in the lateral directional radiation direction.

[0027] In one embodiment, the positional relationship between the electric field isolator and the planar antenna is adjustable.

[0028] In one embodiment, the electric field isolator is configured in a modular form, allowing for morphological adjustment of the electric field isolator based on the movement between the modular components.

[0029] In one embodiment, the electric field isolator is provided as a hemispherical metal layer, wherein the forward convergent surface and the backward repulsive surface are formed on the inner and outer surfaces of the hemispherical metal layer, respectively.

[0030] In one embodiment, R1 = λ / 4, R2 = λ / 2, and θ1 = 120°.

[0031] In one embodiment, at least two of the planar antennas are arrayed on the same circuit board, and the array layout of the improved antenna is formed based on the arrangement of a corresponding number of the electric field isolators.

[0032] In one embodiment, the planar antenna has its original directional radiation direction as the direction from the reference ground toward the planar radiation source, and at least two planar antennas are arranged back-to-back with their original directional radiation directions facing away from each other.

[0033] In one embodiment, the two planar antennas arranged back-to-back share a reference ground, corresponding to a back-to-back structure in which the two planar radiation sources are arranged at intervals from the reference ground, with the reference ground as the boundary.

[0034] In one embodiment, a second cone is defined with the origin O of the three-dimensional coordinate system as the vertex and the positive Y-axis as the axis, wherein the vertex angle θ2 of the cross section of the second cone in the XOY plane satisfies θ2≥120°, and the space jointly defined by the first sphere, the second sphere and the outer surface of the second cone is defined as a second space, wherein the electric field isolator is located in the second space.

[0035] In one embodiment, the electric field isolator further has a reverse blocking surface opposite to the lateral beam-gathering surface, wherein the reverse blocking surface has a second cross section intercepted by the first space, and in the state where the first cone has the second cross section as its bottom surface, the bottom surface can independently form a shielding effect on a conical beam of light with the origin O of the three-dimensional coordinate system as its source point and an angle of 46° inside the first cone.

[0036] In one embodiment, the electric field isolator further has at least one annular groove to form at least one choke based on the arrangement of the annular groove, thereby suppressing the radiated energy of the improved antenna in the rear space.

[0037] The further objects and advantages of the invention will become fully apparent from the following description and accompanying drawings. Attached Figure Description

[0038] Figure 1 The structure of an existing planar antenna and a corresponding radiation pattern and S11 curve diagram are shown.

[0039] Figure 2 This is a diagram illustrating the radiation principle of a planar radiation source for an existing planar antenna based on its self-coupling.

[0040] Figure 3 This is a radiation principle diagram of an improved antenna according to an embodiment of the present invention.

[0041] Figure 4Aand 4B This is a schematic diagram showing the positional relationship between the planar antenna and the electric field isolator of the improved antenna, defined based on a three-dimensional coordinate system.

[0042] Figure 5A An antenna structure based on the radiation principle of the improved antenna according to the above embodiments of the present invention, and a radiation pattern and S11 curve corresponding to the antenna structure.

[0043] Figure 5B This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0044] Figure 5C This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0045] Figure 5D This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0046] Figure 5E This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0047] Figure 6A This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0048] Figure 6B This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0049] Figure 7A This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0050] Figure 7B This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0051] Figure 8A This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0052] Figure 8B This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0053] Figure 9A This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0054] Figure 9B This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0055] Figure 9C This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0056] Figure 10 This invention provides another antenna structure based on the radiation principle of the improved antenna described in the above embodiments, along with a radiation pattern and S11 curve corresponding to that antenna structure.

[0057] Figure 11A This is a schematic diagram of the structure of a planar antenna according to the above-described embodiment of the present invention.

[0058] Figure 11B This is a schematic diagram of another planar antenna according to the above-described improved antenna of the present invention.

[0059] Figure 11C This is a schematic diagram of another planar antenna according to the above-described improved antenna of the present invention.

[0060] Figure 11D This is a schematic diagram of another planar antenna according to the above-described improved antenna of the present invention.

[0061] Figure 11E This is a schematic diagram of another planar antenna according to the above-described improved antenna of the present invention.

[0062] Figure 12A This is a schematic diagram of another planar antenna according to the above-described improved antenna of the present invention.

[0063] Figure 12B This is a schematic diagram of another planar antenna according to the above-described improved antenna of the present invention.

[0064] Figure 13This is a schematic diagram of another antenna structure based on the radiation principle of the improved antenna according to the above embodiments of the present invention.

[0065] Figure 14 This is a schematic diagram of another antenna structure based on the radiation principle of the improved antenna according to the above embodiments of the present invention.

[0066] Figure 15A This is a schematic diagram of an array layout for the improved antenna according to the above embodiments of the present invention.

[0067] Figure 15B This is a schematic diagram of another array layout of the improved antenna according to the above embodiments of the present invention.

[0068] Figure 15C This is a schematic diagram of another array layout of the improved antenna according to the above embodiments of the present invention.

[0069] Figure 16A and Figure 16B This is a schematic diagram of another array layout of the improved antenna according to the above embodiments of the present invention and a radiation pattern corresponding to the array layout. Detailed Implementation

[0070] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0071] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0072] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the elements can be multiple, and the term "a" should not be understood as a limitation on the number.

[0073] This invention provides an improved planar antenna with lateral directional beamforming and reverse spatial rejection. Compared to a conventional planar antenna with directional radiation characteristics, the improved antenna has a directional radiation direction that deviates laterally from the original directional radiation direction, and exhibits electromagnetic radiation rejection characteristics in the reverse space of this lateral directional radiation direction. Consequently, the improved antenna has good applicability and anti-interference performance in the field of directional microwave detection. To fully understand the structural principle of the improved antenna, the electromagnetic induction radiation principle of the planar antenna based on the reactive field generated by its own coupling is illustrated. See the accompanying drawings for details. Figure 2 As shown, the planar antenna 10 includes a reference ground 11 and a planar radiation source 12, which are arranged in the form of planar metal layers and spaced apart in a parallel state. In order to form the structure in which the reference ground 11 and the planar radiation source 12 are spaced apart in a parallel state, the reference ground 11 and the planar radiation source 12, which are arranged in the form of planar metal layers, are usually mounted on two opposite surfaces of the same circuit board, or the reference ground 11 and the planar radiation source 12, which are arranged in the form of planar metal layers, are respectively mounted on two circuit boards, and the structure in which the reference ground 11 and the planar radiation source 12 are spaced apart in a parallel state is formed based on the fixation between the two circuit boards. The planar radiation source 12 is positioned off-center from its physical center point to receive a feed signal for feeding. This feeding method includes, but is not limited to, at least one of the following feeding structures: probe feeding, microstrip feeding, edge feeding, and corner feeding. Correspondingly, the planar antenna 10 can form an initial polarization and have a polarization direction in the fed state. In the fed state of the planar antenna 10, the planar radiation source 12 establishes a reactive field in the polarization direction based on its own coupling, with the physical center point of the planar radiation source 12 as the radiation source point. This reactive field generates an induced magnetic field based on electromagnetic induction, and the induced magnetic field generates an induced electric field based on electromagnetic induction, thus forming electromagnetic radiation based on electromagnetic induction. The reactive field is one of the most primitive electric fields generated by the planar antenna 10 in the fed state, and its range corresponds to… Figure 2 The schematic two-dimensional reactive field is concentrated on both sides of the planar radiation source 12 along the polarization direction. From the perspective of the antenna's radiation principle, the reactive field is an energy storage field rather than a radiation field. That is, the conversion between the electric field and the magnetic field in the reactive field is similar to the conversion between the electric field and the magnetic field in a transformer. It is an inductive field and does not radiate energy outward.

[0074] The improved antenna of the present invention, based on the structure of the planar antenna 10, forms a conductive surface along the reactive field direction of the planar antenna 10 that meets certain size and area requirements and a certain distance requirement between the conductive surface and the planar antenna 10. This allows the electromagnetic induction of the reactive field of the planar antenna 10 on one side of the planar radiation source 12 (the space opposite to the aforementioned lateral directional radiation direction) to be blocked by the conductive surface. The blocked reactive field energy can be fed back to the planar antenna 10 through the conductive surface with low or even no loss. Correspondingly, the electromagnetic radiation generated by electromagnetic induction on that side of the improved antenna can be blocked, resulting in a low back lobe radiation characteristic in the radiation pattern. On the other side (the aforementioned lateral directional radiation direction), the improved antenna has a focused and enhanced radiation beam. The required dimensions and area of ​​the conductive surface along the reactive field direction of the planar antenna 10 are designed to form a closed loop of the reactive field in the reverse space of the planar antenna 10, thereby preventing the generation of an induced magnetic field. This allows the electromagnetic induction of the reactive field of the planar antenna 10 in the reverse space to be blocked, resulting in directional radiation of the improved antenna in the lateral direction. The required distance between the conductive surface and the planar antenna 10 is designed to reduce the coupling loss between them. This allows the reactive field energy blocked by the conductive surface to be fed back to the planar antenna 10 with low or no loss, resulting in a low backlobe radiation characteristic in the radiation pattern and a focused and enhanced radiation beam in the lateral directional radiation direction.

[0075] Therefore, please refer to the accompanying drawings in the specification of this invention. Figure 3 An improved antenna according to an embodiment of the present invention is exemplified, wherein the improved antenna further includes an electric field isolator 20 disposed of as a conductive material on the basis of the structure of the planar antenna 10, so as to laterally and directionally enhance the reactive field of the planar antenna 10 based on the structure of the electric field isolator 20 and its positional relationship with the planar antenna 10, thereby causing the improved antenna to exhibit lateral directional radiation characteristics and having a beam of radiation that is clustered and enhanced in the lateral directional radiation direction.

[0076] Specifically, the electric field isolator 20 has a lateral focusing surface 21. Based on the structure of the electric field isolator 20 and its positional relationship with the planar antenna 10, the lateral focusing surface 21 can form the aforementioned conductive surface by satisfying certain size requirements in the reactive field of the planar antenna 10 along the reactive field direction and satisfying certain distance requirements between the planar antenna 10 and the planar antenna 10. This allows the electromagnetic induction of the reactive field of the planar antenna 10 in the reverse space to be blocked by the lateral focusing surface 21, and the blocked reactive field energy can be fed back to the planar antenna 10 through the lateral focusing surface 21 with low or even no loss. Correspondingly, the electromagnetic radiation generated by the electromagnetic induction in the reverse space of the improved antenna can be blocked, resulting in a low back lobe or even no positive back lobe radiation characteristic in the radiation pattern, and the improved antenna has a radiation beam enhanced by focusing in the lateral directional radiation direction.

[0077] Furthermore, combined Figure 2 and Figure 3 Referring to the accompanying drawings of this invention Figure 4A and Figure 4B To clearly define the structure of the electric field isolator 20 and its positional relationship with the planar antenna 10, the present invention corresponds to... Figure 4A and Figure 4B A three-dimensional coordinate system is introduced with the physical center point of the planar radiation source 12 as the origin O. An X-axis and a Y-axis of the three-dimensional coordinate system are established on the planar radiation source 12 along the polarization direction of the planar antenna 10. The Z-axis of the three-dimensional coordinate system is perpendicular to the planar radiation source 12. A first sphere 101 is defined with the origin O of the three-dimensional coordinate system as its center and a first radius R1 as its radius. A second sphere 102 is defined with the origin O of the three-dimensional coordinate system as its center and a second radius R2 greater than R1 as its radius. A first cone 103 is defined with the origin O of the three-dimensional coordinate system as its vertex and the negative Y-axis as its axis. The apex angle of the first cone 103 in the XOY plane is θ1. The inner diameter of the first sphere 101, the second sphere 102, and the first cone 103 is defined. The space jointly defined by the sides is a first space 100. The lateral beam-gathering surface 21 has a first cross-section 211 intercepted by the first space 100. In the state where the first cone 103 has the first cross-section 211 as its base, this base can independently block a conical beam of light with a source point of 46° originating from the origin O of the three-dimensional coordinate system inside the first cone 103. That is, the beam of light inside the first cone 103, with the first cross-section 211 as its independent base, cannot completely exit from this base. (Referring to...) Figure 2The reactive field range of the planar antenna 10 is shown in the figure. The values ​​of R1, R2 and θ1 are set in the range of λ / 8≤R1<R2<3λ / 4 and θ1≥120°, where λ is a wavelength parameter corresponding to the operating frequency of the planar antenna 10, so that the first cross section 211 of the lateral beamforming surface 21 can form the conductive surface that meets the aforementioned requirements. This allows the electromagnetic induction generated by the reactive field of the planar antenna 10 based on the coupling of the planar radiation source 12 in the reverse space (the space bounded by the XOZ plane of the three-dimensional coordinate system towards the negative Y-axis) to be blocked by the lateral focusing surface 21. The blocked reactive field energy can be fed back to the planar antenna 10 through the lateral focusing surface 21 with low or even no loss. This results in the electromagnetic radiation generated by the improved antenna based on electromagnetic induction in the reverse space being blocked, exhibiting a low back lobe in the radiation pattern. It also allows the improved antenna to have a focused and enhanced radiation beam in the lateral directional space (the space bounded by the XOZ plane of the three-dimensional coordinate system towards the positive Y-axis), exhibiting directional radiation characteristics with the lateral direction as the directional radiation direction.

[0078] It is worth noting that, in the above description of the present invention, the description of "establishing the X-axis of the three-dimensional coordinate system along the polarization direction of the planar antenna 10 on the planar radiation source 12" does not constitute a limitation on the positive or negative orientation of the X-axis of the three-dimensional coordinate system. That is, the polarization direction of the planar antenna 10 can be either the positive or negative X-axis of the three-dimensional coordinate system.

[0079] Understandably, based on Figure 2 The reactive field range of the planar antenna 10 shown is set in the range of R2 < 3λ / 4. The value of R2 is because a complete induced magnetic field cannot be formed within a distance of λ / 4 from the reactive field of the planar antenna 10. Therefore, the setting of the corresponding conductive surface can still block the electromagnetic induction of the reactive field of the planar antenna 10 in the opposite space. However, there is a certain loss compared to setting the corresponding conductive surface within the reactive field range of the planar antenna 10. Therefore, the value of R2 can be set in the range of R2 < 3λ / 4, and preferably in the range of R2 ≤ λ / 2.

[0080] It is worth mentioning that, when the first cone 103 has the first cross-section 211 as its bottom surface, this bottom surface can independently block a conical beam of light with a source point of 46° originating from the origin O of the three-dimensional coordinate system inside the first cone 103. In other words, the lateral focusing surface 21 is not limited to a continuous surface, nor is it limited to a two-dimensional plane; it can be a surface with holes and / or grooves, including both planar and non-planar surfaces. As long as the first cross-section 211, when serving as the bottom surface of the first cone 103, can block a conical beam of light with a source point of 46° originating from the origin O of the three-dimensional coordinate system inside the first cone 103, the lateral focusing surface 21 can form the conductive surface that satisfies the aforementioned requirements.

[0081] It is understood that in the description of the present invention, the introduction of "conical beam with an angle of 46°" is only for the convenience of understanding the state in which the electric field isolator 20 has holes and / or slots. The hole size and slot size that the first cross section 211 is allowed to form at different distances from the origin O of the three-dimensional coordinate system do not constitute a limitation on whether the improved antenna of the present invention has the conical beam or whether it can form the conical beam.

[0082] Furthermore, it is worth mentioning that the reactive field of the planar antenna 10 is an induced field and does not radiate energy outward. That is, when the lateral focusing surface 21 is located in the reactive field of the planar antenna 10, the lateral focusing surface 21 does not exhibit reflection behavior during the lateral directional radiation of the improved antenna based on electromagnetic induction. However, when the improved antenna is used as a receiving antenna independently or simultaneously, the reflection capability of the lateral focusing surface 21 on the electromagnetic radiation of the lateral directional space is not limited. The electromagnetic radiation of the lateral directional space can still be reflected by the lateral focusing surface 21 and received by the planar antenna 10, thereby improving the receiving sensitivity of the improved antenna when used as a receiving antenna independently or simultaneously.

[0083] Furthermore, a second cone 104 is defined with the origin O of the three-dimensional coordinate system as the vertex and the positive Y-axis as the axis. The vertex angle θ2 of the cross section of the second cone 104 in the XOY plane satisfies θ2≥120°. The space defined by the first sphere 101, the second sphere 102, and the outer surface of the second cone 104 is defined as a second space 200. The electric field isolator 20 is preferably located within the second space 200 to avoid the extension of the electric field isolator 20 outside the second space 200, especially its extension within the second cone 104, which would damage the lateral focusing characteristics and reverse reception rejection characteristics of the improved antenna.

[0084] Continue to combine Figure 2 and Figure 3 Referring to the accompanying drawings of this invention Figure 4A and Figure 4B The electric field isolator 20 further has a reverse blocking surface 22 opposite to the lateral beam-gathering surface 21. The reverse blocking surface 22 has a second cross section 221 cut off by the first space 100. When the first cone 103 has the second cross section 221 as its bottom surface, the bottom surface can independently block a conical beam of light with the origin O of the three-dimensional coordinate system as its source point and an angle of 46° inside the first cone 103. That is, the beam of light inside the first cone 103 with the second cross section 211 as its bottom surface cannot be completely emitted from the bottom surface. This makes it so that the electromagnetic radiation in the reverse space cannot be received by the planar antenna 10 in the form of electromagnetic waves by diffraction, nor can it affect the planar antenna 10 based on the coupling between the reverse blocking surface 22 and the planar antenna 10 when it is received by the reverse blocking surface 22. Correspondingly, the reception rejection characteristics of the improved antenna for electromagnetic radiation in the reverse space can be further enhanced based on the design of the reverse blocking surface 22 that meets the aforementioned requirements.

[0085] It is understood that the conductive material forming the lateral convergence surface 21 must have a conductive surface opposite to the lateral convergence surface 21. However, the conductive surface may not necessarily meet the conditions for forming the reverse rejection surface 22 based on the structural morphology of the conductive material. Or, when the conductive surface meets the conditions for forming the reverse rejection surface 22, the conductive surface may not have the function of the reverse rejection surface 22 due to the rearward blocking of the conductive surface by other conductive materials. Therefore, the present invention does not limit the coexistence of the reverse rejection surface 22 and the lateral convergence surface 21.

[0086] Specifically, based on the actual field strength distribution of the reactive field of the planar antenna 10, the first radius R1 and the second radius R2 can be λ / 8 = R1 < R2, and R2 tends to 3λ / 4. Preferably, λ / 4 = R1 < R2, and R2 tends to 3λ / 4. More preferably, λ / 4 = R1 < R2 = λ / 2. This enhances the blocking capability of the lateral focusing surface 21 against the electromagnetic induction of the reactive field of the planar antenna 10 in reverse space, while further increasing the distance between the lateral focusing surface 21 and the planar antenna 10. This further reduces the loss caused by coupling between the lateral focusing surface 21 and the planar antenna 10, thereby helping to suppress the back lobe of the improved antenna in the radiation pattern and enhance the radiation gain of the improved antenna in the lateral directional radiation direction.

[0087] Specifically, refer to the accompanying drawings of the specification of this invention. Figures 5A to 10As shown, to fully disclose the present invention, different structures of the improved antenna according to the above embodiments of the present invention, the radiation patterns corresponding to the structures, and the S11 curves are illustrated respectively.

[0088] In these structural examples of the present invention, the planar radiation source 12 of the planar antenna 10 is fed by a probe-feed structure. The planar radiation source 12 has at least one feed point. Specifically, in these structural examples of the present invention, the planar radiation source 12 has one and only one feed point. The planar radiation source 12 is disposed at the feed point and fed by a corresponding feed signal. The polarization direction of the planar antenna 10 is the direction of the line connecting the feed point of the planar radiation source 12 to the physical center point of the planar radiation source 12. Then, the X-axis of the corresponding three-dimensional coordinate system is located on the line connecting the physical center point of the planar radiation source 12 and the feed point.

[0089] Corresponding to Figures 5A to 5E As shown, the electric field isolator 20 is provided with a hemispherical metal layer / panel with an inner radius of R, wherein the center of the hemispherical electric field isolator 20 is located at the origin O of the three-dimensional coordinate system, and the plane of the circular opening of the electric field isolator 20 provided with a hemispherical metal layer / panel is perpendicular to the Y-axis of the three-dimensional coordinate system.

[0090] Specifically Figure 5A In the illustrated improved antenna, the electric field isolator 20 is provided with a hemispherical metal layer / panel with an inner radius of λ / 4, such that the lateral focusing surface 21 and the reverse blocking surface 22 satisfying the aforementioned requirements are formed on the inner and outer surfaces of the hemispherical electric field isolator 20, respectively. At this time, the lateral directional radiation direction of the improved antenna corresponds to the positive Y-axis of the three-dimensional coordinate system, and the improved antenna has a radiation gain of up to 3.90 dBi in the lateral directional radiation direction, far exceeding... Figure 1 The illustrated planar antenna exhibits a significantly enhanced beamwidth in the lateral directional radiation direction, with the radiation gain in the opposite direction reduced to below -3 dBi. Particularly, the positive backlobe radiation gain in the opposite direction is reduced to below -9 dBi. Therefore, the overall gain relative to... Figure 1 The planar antenna shown has a significantly suppressed back lobe, which is beneficial for ensuring the detection sensitivity of the improved antenna in the lateral directional radiation direction, and for achieving the rejection of electromagnetic radiation from the opposite space by the improved antenna based on the reciprocal characteristics of the antenna.

[0091] Corresponding to Figure 5B ,exist Figure 5ABased on the structure of the improved antenna shown, the inner radius R of the electric field isolator 20, which is provided with a hemispherical metal layer / panel, is enlarged to 3λ / 8. The inner and outer surfaces of the hemispherical electric field isolator 20 can still form the lateral focusing surface 21 and the reverse rejection surface 22, respectively, satisfying the aforementioned requirements. At this time, the back lobe size of the improved antenna in reverse space is relative to... Figure 5A The radiation is further suppressed, while the improved antenna has a radiation gain of up to 4.96 dBi in the lateral directional radiation direction.

[0092] Corresponding to Figure 5C ,exist Figure 5A Based on the structure of the improved antenna shown, the inner radius R of the electric field isolator 20, which is provided with a hemispherical metal layer / panel, is enlarged to λ / 2. The inner and outer surfaces of the hemispherical electric field isolator 20 can still form the lateral focusing surface 21 and the reverse rejection surface 22, respectively, satisfying the aforementioned requirements. At this time, the back lobe size of the improved antenna in reverse space is relative to... Figure 5B The radiation is further suppressed, while the improved antenna has a radiation gain of up to 6.15 dBi in the lateral directional radiation direction.

[0093] Corresponding to Figure 5D ,exist Figure 5A Based on the structure of the improved antenna shown, the inner radius R of the electric field isolator 20, which is provided with a hemispherical metal layer / panel, is enlarged to 5λ / 8. The inner and outer surfaces of the hemispherical electric field isolator 20 can still form the lateral focusing surface 21 and the reverse rejection surface 22, respectively, satisfying the aforementioned requirements. At this time, although the back lobe of the improved antenna in reverse space is relative to... Figure 5C While the gain has increased somewhat, the improved antenna's radiation gain in reverse space remains below -3 dBi overall, maintaining significant practical value. Furthermore, the improved antenna still exhibits clear lateral directional radiation characteristics, with a radiation gain as high as 5.20 dBi in the lateral directional radiation direction, relative to... Figure 1 The planar antenna shown still exhibits significant advantages in low back lobe and high gain.

[0094] Corresponding to Figure 5E ,exist Figure 5A Based on the structure of the improved antenna shown, the inner radius R of the electric field isolator 20, which is provided with a hemispherical metal layer / panel, is enlarged to 3λ / 4. The inner and outer surfaces of the hemispherical electric field isolator 20 can still form the lateral focusing surface 21 and the reverse rejection surface 22, respectively, satisfying the aforementioned requirements. At this time, the back lobe of the improved antenna in reverse space relative to... Figure 5DWhile the gain has increased somewhat, the improved antenna still exhibits significant lateral directional radiation characteristics and boasts a radiation gain of up to 7.41 dBi in the lateral directional radiation direction, relative to... Figure 1 The planar antenna shown still exhibits significant advantages in low back lobe and high gain. Therefore, it is reasonable to set the first radius R1 and the second radius R2 to satisfy R1 < R2 < 3λ / 4.

[0095] Corresponding to Figure 6A The electric field isolator 20 is defined as the portion of a spherical metal layer / panel with an inner radius of R and a center located at the origin O of the three-dimensional coordinate system, intercepted by the inner surface of the first cone 103, where R = λ / 2. The apex angle θ1 of the cross-section of the first cone 103 in the XOY plane satisfies θ1 = 150°. At this time, the improved antenna can still exhibit obvious lateral directional radiation characteristics. The lateral directional radiation direction has a certain angular deflection relative to the positive Y-axis of the three-dimensional coordinate system, making it suitable for detection scenarios with certain tilt angle requirements. The radiation gain in the lateral directional radiation direction is also as high as 6.13 dBi, while the overall gain is relatively high compared to the XOY plane. Figure 1 The planar antenna shown has a significantly suppressed back lobe, which can further suppress the back lobe, especially when applied to detection scenarios with certain tilt angle requirements. This is beneficial to ensuring the detection sensitivity of the improved antenna in the lateral directional radiation direction, and to achieving the rejection of electromagnetic radiation from the opposite space by the improved antenna based on the antenna's reciprocal transmit and receive characteristics.

[0096] Corresponding to Figure 6B ,exist Figure 6A Based on the illustrated structure, the apex angle θ1 of the first cone 103 in the XOY plane satisfies θ1 = 120°. At this point, the improved antenna still exhibits significant lateral directional radiation characteristics. This lateral directional radiation direction has a certain angular deflection relative to the positive Y-axis of the three-dimensional coordinate system, making it suitable for detection scenarios with certain tilt angle requirements. Furthermore, the radiation gain in the lateral directional radiation direction is as high as 5.57 dBi. Simultaneously, the overall gain relative to... Figure 1 The planar antenna shown has a significantly suppressed positive back lobe, which can further suppress the back lobe when applied to detection scenarios with certain tilt angle requirements. Therefore, it still has significant practical value. In other words, it is reasonable to set the apex angle θ1 of the first cone 103 in the XOY plane to satisfy θ1≥120°.

[0097] Corresponding to Figure 7AThe electric field isolator 20 is defined as the portion of a spherical metal layer / panel with an inner radius of R and a center located at the origin O of the three-dimensional coordinate system, intercepted by the outer surface of the second cone 104, where R = λ / 2. The apex angle θ2 of the cross-section of the second cone 104 in the XOY plane satisfies θ2 = 150°. Correspondingly, the inner and outer surfaces of the electric field isolator 20 can still form the lateral beamforming surface 21 and the reverse rejection surface 22, respectively, satisfying the aforementioned requirements. At this time, the improved antenna can still exhibit obvious lateral directional radiation characteristics, and the radiation gain in the lateral directional radiation direction is as high as 5.51 dBi. At the same time, the overall radiation gain in the reverse space in this lateral direction is reduced to below -6 dBi, especially the positive back lobe radiation gain in the reverse space in this lateral direction is reduced to below -9 dBi. Therefore, the overall gain is significantly lower than that in the reverse space. Figure 1 The planar antenna shown has a significantly suppressed back lobe and a significantly enhanced directional radiation gain, which is beneficial for ensuring the detection sensitivity of the improved antenna in the lateral directional radiation direction and for achieving the rejection of electromagnetic radiation from the opposite space by the improved antenna based on the antenna's reciprocal transmit and receive characteristics.

[0098] Corresponding to Figure 7B ,exist Figure 7A Based on the illustrated structure, the apex angle θ2 of the cross-section of the second cone 104 in the XOY plane satisfies θ2 = 120°. At this point, the improved antenna still exhibits significant lateral directional radiation characteristics, and its radiation gain in the directional radiation direction is as high as 4.73 dBi. Although relative to... Figure 7A Although the improved antenna has a significantly increased positive back lobe, its maximum radiation gain in reverse space remains at around -9 dBi, which still has significant practical value. Therefore, it is reasonable to set the apex angle θ2 of the cross section of the second cone 104 in the XOY plane to satisfy θ1≥120°.

[0099] Corresponding to Figure 8A and Figure 8B ,exist Figure 5C Based on the structure of the improved antenna shown, the electric field isolator 20, which is provided with a hemispherical metal layer / panel, is rotated counterclockwise by 15° and 30° around the X-axis of the three-dimensional coordinate system, respectively. This is equivalent to... Figure 5CBased on the structure of the improved antenna shown, the planar antenna 10 is rotated clockwise by 15° and 30° around the X-axis of the three-dimensional coordinate system, respectively. A hemispherical metal layer / panel with a radius of λ / 2 is provided within the electric field isolator 20, wherein the center of the hemispherical electric field isolator 20 is located at the origin O of the three-dimensional coordinate system. The plane containing the circular opening of the electric field isolator 20, with the hemispherical metal layer / panel as its center, is rotated counterclockwise by 15° and 30° relative to the Y-axis perpendicular to the three-dimensional coordinate system, respectively, around the X-axis of the three-dimensional coordinate system. Accordingly, the improved antenna exhibits significant lateral directional radiation characteristics, and this lateral directional radiation direction has a certain angular deflection relative to the positive Y-axis of the three-dimensional coordinate system, making it suitable for detection scenarios requiring a certain tilt angle. Furthermore, the radiation gain in the lateral directional radiation direction is higher than 6.40 dBi, and the overall gain is also higher than 6.40 dBi. Figure 1 The planar antenna shown has a significantly suppressed back lobe, which can further suppress the back lobe, especially when applied to detection scenarios with certain tilt angle requirements. This is beneficial to ensuring the detection sensitivity of the improved antenna in the lateral directional radiation direction, and to achieving the rejection of electromagnetic radiation from the opposite space by the improved antenna based on the antenna's reciprocal transmit and receive characteristics.

[0100] Corresponding to Figure 9A and Figure 9B ,exist Figure 5C Based on the structure of the improved antenna shown, the electric field isolator 20, which is provided with a hemispherical metal layer / panel, is rotated clockwise by 15° and 30° around the X-axis of the three-dimensional coordinate system, respectively. This is equivalent to... Figure 5C Based on the structure of the improved antenna shown, the planar antenna 10 is rotated counterclockwise by 15° and 30° around the X-axis of the three-dimensional coordinate system, respectively. A hemispherical metal layer / panel with a radius of λ / 2 is provided within the electric field isolator 20, wherein the center of the hemispherical electric field isolator 20 is located at the origin O of the three-dimensional coordinate system. The plane containing the circular opening of the electric field isolator 20, with the hemispherical metal layer / panel as its center, is rotated clockwise by 15° and 30° relative to the Y-axis perpendicular to the three-dimensional coordinate system, respectively, around the X-axis of the three-dimensional coordinate system. Accordingly, the improved antenna exhibits obvious lateral directional radiation characteristics, and this lateral directional radiation direction has a certain angular deflection relative to the positive Y-axis of the three-dimensional coordinate system, making it suitable for detection scenarios requiring a certain tilt angle. The radiation gain in the lateral directional radiation direction is also higher than 4.30 dBi, while the overall gain relative to the X-axis is also higher. Figure 1The planar antenna shown has a significantly suppressed back lobe, which can further suppress the back lobe, especially when applied to detection scenarios with certain tilt angle requirements. This is beneficial to ensuring the detection sensitivity of the improved antenna in the lateral directional radiation direction, and to achieving the rejection of electromagnetic radiation from the opposite space by the improved antenna based on the antenna's reciprocal transmit and receive characteristics.

[0101] Corresponding to Figure 9C ,exist Figure 5C Based on the structure of the improved antenna shown, the electric field isolator 20, which is provided with a hemispherical metal layer / panel, is rotated 45° clockwise around the X-axis of the three-dimensional coordinate system, which is equivalent to... Figure 5C Based on the structure of the improved antenna shown, the planar antenna 10 is rotated 45° counterclockwise around the X-axis of the three-dimensional coordinate system. A hemispherical metal layer / panel with a radius of λ / 2 is provided within the electric field isolator 20. The center of the hemispherical electric field isolator 20 is located at the origin O of the three-dimensional coordinate system. The plane containing the circular opening of the electric field isolator 20, with the hemispherical metal layer / panel as its center, is rotated 45° clockwise around the X-axis of the three-dimensional coordinate system relative to the Y-axis perpendicular to the three-dimensional coordinate system. Accordingly, the improved antenna exhibits significant lateral directional radiation characteristics, and this lateral directional radiation direction has a certain angular deflection relative to the positive Y-axis of the three-dimensional coordinate system, making it suitable for detection scenarios requiring a certain tilt angle. Simultaneously, the overall structure... Figure 1 The planar antenna shown has a significantly suppressed back lobe, which can further suppress the back lobe, especially when applied to detection scenarios with certain tilt angle requirements. This is beneficial to ensuring the detection sensitivity of the improved antenna in the lateral directional radiation direction, and to achieving the rejection of electromagnetic radiation from the opposite space by the improved antenna based on the antenna's reciprocal transmit and receive characteristics.

[0102] It is worth mentioning that the electric field isolator 20 can have various forms, as long as it has the lateral convergence surface 21 that meets the aforementioned requirements, and preferably further has the reverse rejection surface 22 that meets the aforementioned requirements. Accordingly, the specific form of the electric field isolator 20 does not constitute a limitation on the present invention. Furthermore, the electric field isolator 20 can be an independent conductor, such as a metallic body and a non-metallic body with conductive properties (such as a carbon-based material with conductive properties), or a conductor supported on an insulating material, such as a conductor formed on an insulating material by processes such as electroplating, spraying, or doping, or a conductor with conductive properties formed based on the interaction between different materials, such as a conductor formed based on the doping of semiconductors. The present invention does not limit this.

[0103] Example, referring to the accompanying drawings of the specification of the present invention. Figure 10 As shown, in this structural example of the improved antenna of the present invention, the electric field isolator 20 is configured with a rectangular bottom surface and a corresponding rectangular opening. Accordingly, the improved antenna still exhibits significant lateral directional radiation characteristics. This lateral directional radiation direction has a certain angular deflection relative to the positive Y-axis of the three-dimensional coordinate system, making it suitable for detection scenarios requiring a certain tilt angle. Furthermore, the radiation gain in the lateral directional radiation direction is as high as 6.04 dBi. Simultaneously, the overall gain relative to... Figure 1 The planar antenna shown has a significantly suppressed back lobe, which can further suppress the back lobe, especially when applied to detection scenarios with certain tilt angle requirements. This is beneficial to ensuring the detection sensitivity of the improved antenna in the lateral directional radiation direction, and to achieving the rejection of electromagnetic radiation from the opposite space by the improved antenna based on the antenna's reciprocal transmit and receive characteristics.

[0104] It is understood that, when changes in the structural form of the electric field isolator 20 and its position relative to the planar antenna 10 correspond to the aforementioned structural example and can adjust the beam deflection angle of the improved antenna, in some embodiments of the present invention, the positional relationship between the electric field isolator 20 and the planar antenna 10 of the improved antenna is adjustable, and in other embodiments of the present invention, the form of the electric field isolator 20 is adjustable, such as by setting the electric field isolator 20 in a split form so that the form of the electric field isolator 20 can be adjusted based on the movement between the split parts (such as relative rotation movement, relative translation movement). Thus, the beam deflection angle of the improved antenna is adjusted based on the adjustment of the positional relationship between the electric field isolator 20 and the planar antenna 10, and / or based on the adjustment of the form of the electric field isolator 20, so that the improved antenna can meet different detection requirements and has better applicability.

[0105] It is understood that in these structural examples of the present invention, the planar antenna 10 corresponds to Figure 11A The example of feeding using a probe-feed structure does not constitute a limitation on the feeding structure of the planar antenna 10 of the present invention. The planar antenna 10 can be fed using at least one of the following feeding structures: probe-feed structure, microstrip-feed structure, side-feed structure, and corner-feed structure. Specifically, an example is given of the planar antenna 10 being fed at a single feeding position. The structures of the planar antenna 10 employing different feeding structures... Figures 11A to 11E Further examples are provided.

[0106] exist Figure 11AIn the illustrated feeding structure, the planar radiating source 12 has one and only one feeding point 121, which is offset from the physical center point of the planar radiating source 12. This corresponds to the planar radiating source 12 being fed by a corresponding feeding signal at the feeding point 121. The polarization direction of the planar antenna 10 is the direction of the line connecting the feeding point 121 of the planar radiating source 12 to the physical center point of the planar radiating source 12. Therefore, the X-axis of the corresponding three-dimensional coordinate system lies on the line connecting the physical center point of the planar radiating source 12 and the feeding point.

[0107] exist Figure 11B In the illustrated feeding structure, the planar radiating source 12 is designed to be fed using a microstrip feeding structure. The planar radiating source 12 is fed via a microstrip line 122 connected to it. In this fed state, the polarization direction of the planar antenna 10 is the direction of the line connecting the point where the planar radiating source 12 is connected to the microstrip line 122 to the physical center point of the planar radiating source 12. Therefore, the X-axis of the corresponding three-dimensional coordinate system lies on this line.

[0108] exist Figure 11C In the illustrated feeding structure, the planar radiating source 12 is designed with a side-feed structure, meaning the planar radiating source 12 is fed via a side feed line 123 coupled to it. In this fed state, the polarization direction of the planar antenna 10 is the direction of the line connecting the center of the side feed line 123 to the physical center point of the planar radiating source 12. Therefore, the X-axis of the corresponding three-dimensional coordinate system lies on this line.

[0109] exist Figure 11D and 11E In the illustrated feeding structure, the planar radiation source 12 is designed to be fed in an angle-feed structure, and the planar radiation source 12 is fed by any one of the following feeding structures at at least one corner: a probe feeding structure, a microstrip feeding structure, and a side-feed structure.

[0110] Specifically Figure 11D In the illustrated feeding structure, the planar radiation source 12 is fed by a microstrip line 122 at one corner using a microstrip feeding structure. Corresponding to the state in which the planar radiation source 12 is fed, the polarization direction of the planar antenna 10 is the direction of the line connecting the position of the planar radiation source 12 connected to the microstrip line 122 to the physical center point of the planar radiation source 12.

[0111] Specifically Figure 11EIn the illustrated feeding structure, the planar radiation source 12 is fed by a side feed structure at one corner via a side feed line 123 coupled to it. Corresponding to the state in which the planar radiation source 12 is fed, the polarization direction of the planar antenna 10 is the direction of the line connecting the center position of the side feed line 123 to the physical center point of the planar radiation source 12.

[0112] Further examples are given using the planar antenna 10 fed at different feeding positions, specifically using a probe-fed structure. Figure 12A In the illustrated feeding structure, the planar radiation source 12 is fed differentially by receiving a feed signal with a certain phase difference at two feed points 121. Corresponding to the state in which the planar radiation source 12 is fed, the polarization direction of the planar antenna 10 is parallel to the line connecting the physical center point of the planar radiation source 12 and the two feed points 121. Figure 12B In the illustrated feeding structure, the planar radiation source 12 receives a feed signal with the same phase at two feed points 121. This includes a structure in which the lines connecting the two feed points 121 to the physical center point of the planar radiation source 12 are perpendicular and orthogonal to each other. Corresponding to the state in which the planar radiation source 12 is fed, the polarization direction of the planar antenna 10 can be understood as the direction of the line connecting the midpoint of the line segment connecting the two feed points 121 to the physical center point of the planar radiation source 12.

[0113] It is worth noting that in these structural examples of the improved antenna of the present invention, the planar radiation source 12 of the planar antenna 10 is one, and the number of planar radiation sources 12 does not constitute a limitation on the improved antenna for a single planar antenna 10. That is, in some structures of the improved antenna of the present invention, the number of planar radiation sources 12 of the planar antenna 10 can be multiple, to equivalently form multiple planar antennas 10 with a single planar radiation source 12, and the present invention does not limit this.

[0114] For example, when there are multiple planar radiation sources 12 in the planar antenna 10, these multiple planar radiation sources 12 can be arranged in an array to equivalently form an array arrangement of multiple planar antennas 10 with a single planar radiation source 12. This allows the corresponding array layout of the planar radiation sources 12 to meet the corresponding structural and performance requirements of the improved antenna. In the same improved antenna, the electric field isolator 20 can form a lateral beamforming surface 21 relative to any one of the planar radiation sources 12, satisfying the aforementioned requirements.

[0115] For example, when there are multiple planar antennas 10 or multiple planar radiation sources 12 of the planar antennas 10, two planar antennas 10 can be arranged back-to-back with their original directional radiation directions (reference bottom surface 11 towards planar radiation source 12) facing away from each other, corresponding to a back-to-back structure where the two reference ground surfaces 11 of the two planar antennas 10 are close together, or corresponding to Figure 13 The formation of a back-to-back structure where two planar antennas 10 share a single reference ground 11, and two planar radiation sources 12 are arranged with the reference ground 11 as the boundary and spaced apart from it, is equivalent to a state where the number of planar radiation sources 12 of the same planar antenna 10 is multiple, wherein two planar radiation sources 12 are arranged with the reference ground 11 as the boundary and spaced apart from it in a back-to-back structure. The corresponding improved antenna corresponds to... Figure 13 The back lobe, especially the positive back lobe, in reverse space is significantly suppressed. Simultaneously, the improved antenna exhibits pronounced lateral directional radiation characteristics, with a radiation gain as high as 7.66 dBi in the lateral directional radiation direction. Figure 1 The planar antenna shown exhibits a clear advantage in low back lobe and high gain.

[0116] It is worth mentioning that, by forming a conductive surface in the reactive field of the planar antenna 10 that meets certain size and area requirements along the direction of the reactive field and meets certain distance requirements between the conductive surface and the planar antenna 10, the electromagnetic induction of the reactive field of the planar antenna 10 on one side of the planar radiation source 12 can be blocked by the conductive surface. The blocked reactive field energy can be fed back to the planar antenna 10 through the conductive surface with low or even no loss. Correspondingly, the electromagnetic radiation generated by electromagnetic induction on that side of the improved antenna can be blocked, resulting in a low back lobe radiation characteristic in the radiation pattern. The improved antenna also has a focused and enhanced radiation beam on the other side. The reactive field is the reactive field established by the planar radiation source 12 in the polarization direction of the planar antenna 10 based on its own coupling, with the physical center point of the planar radiation source 12 as the radiation source point. It is not the only reactive field of the planar antenna 10. When the planar antenna 10 is fed, the planar radiation source 12 can also couple with the reference ground 11 to generate a reactive field. However, in the interaction principle between the planar antenna 10 and the electric field isolator 20 of the present invention, it is mainly the interaction between the electric field isolator 20 and the reactive field generated by the planar radiation source 12 based on its own coupling. When the intensity of the reactive field generated by the planar radiation source 12 based on its own coupling is large, the radiation gain of the improved antenna in the lateral directional radiation direction can be enhanced.

[0117] Therefore, in some embodiments of the present invention, the radiation gain of the improved antenna in the lateral directional radiation direction can be further improved by enhancing the reactive field generated by the planar radiation source 12 based on its own coupling.

[0118] Example, referring to the accompanying drawings of the specification of the present invention. Figure 14 As shown, in this structural example of the present invention, the planar radiation source 12 is recessed in the non-polarized direction so that the strength of the reactive field generated by the planar radiation source 12 based on its own coupling can be increased, thereby increasing the radiation gain of the improved antenna in the lateral directional radiation direction.

[0119] Furthermore, to further suppress the radiated energy of the improved antenna in reverse space, the electric field isolator 20 can also further suppress the radiated energy of the improved antenna in reverse space by forming at least one choke based on a corresponding structural arrangement, for example by forming the choke by providing an annular groove in the electric field isolator 20. The present invention is not limited in this respect.

[0120] It is worth mentioning that, when the electric field isolator 20 has the lateral beamforming surface 21 that meets the aforementioned requirements, the radiation pattern of the improved antenna exhibits a significantly enhanced beamforming beam in the lateral directional radiation direction and a low backlobe radiation characteristic in the reverse space. This is beneficial for ensuring the detection sensitivity of the improved antenna in the lateral directional radiation direction and for achieving rejection of electromagnetic radiation in the reverse space based on the antenna's reciprocal transmit / receive characteristics. In other words, the improved antenna can function independently as a transmitting or receiving antenna, or as a transceiver antenna, and has significant advantages over the independent planar antenna 10 in both independent transmitting or receiving and transceiver antenna configurations. Therefore, multiple improved antennas can be combined to achieve separate transmit / receive or array-type antenna layouts, which is not limited by this invention.

[0121] Furthermore, based on the electric field isolator 20 that meets the aforementioned requirements, the improved antenna exhibits low backlobe or even no positive backlobe radiation characteristics in its radiation pattern, thus possessing the characteristic of rejecting electromagnetic radiation from the opposite space. Therefore, when the improved antenna adopts an array layout, the isolation between each improved antenna can be guaranteed, reducing or even avoiding mutual interference between the array-distributed improved antennas. In this way, based on the array layout of the improved antenna, under the time-division multiplexing mechanism, it is possible to form angular / directional / even 360° area coverage, thereby achieving beam circular or / and overlapping concentrated scanning and detection. Therefore, it can be applied in an angular / regional manner to multi-angle / directional detection scenarios of targets, such as angular / multi-angle / 360° rotating stereoscopic scanning detection of the human body or limbs.

[0122] In other words, for the planar antenna 10, since its directional radiation direction is from the reference ground 11 to the planar radiation source 12, and it has a large radiation gain in the reverse space of the directional radiation direction, a multi-antenna array layout on the same circuit board cannot achieve angle / regional detection in three-dimensional space. Furthermore, the multi-antenna array layout will cause backlobe crossings, resulting in poor isolation between antennas and easily causing serious signal crosstalk problems. However, for the improved antenna of the present invention, since the improved antenna exhibits low backlobe radiation characteristics in the radiation pattern and has the characteristic of rejecting electromagnetic radiation in the reverse space, the array layout of the improved antenna can achieve time-division / angle / regional detection in three-dimensional space. Moreover, the improved antennas have good isolation, which can suppress mutual signal crosstalk, thereby ensuring the detection performance in time-division / angle / regional detection.

[0123] For example, such as Figures 15A to 15C As shown, when at least two planar antennas 10 are arrayed on the same circuit board, based on the setting of the corresponding electric field isolators 20 that meet the aforementioned requirements, the array layout of the improved antenna can be formed, thereby forming a 180° or even 360° wide-range detection through beamforming, or performing time-division / angle-division / zone-division detection in the spatial range. When performing time-division / angle-division / zone-division detection, since the improved antenna exhibits low back lobe or even no positive back lobe radiation characteristics in the radiation pattern, it has the characteristic of rejecting electromagnetic radiation in the opposite space. Each of the improved antennas has good isolation and can suppress signal crosstalk between them.

[0124] For example, corresponding to Figure 15AWhen two planar antennas 10 are arrayed on the same circuit board and the electric field isolators 20 that meet the aforementioned requirements are set to form an array layout in which the two improved antennas have mutually perpendicular directional radiation directions, beamforming can be used to form a wide-range detection approaching 180°, or time-division / angle-division / zone-division detection can be performed within a 180° spatial range. When performing time-division / angle-division / zone-division detection, based on the characteristic of the improved antennas to reject electromagnetic radiation in the opposite space, the two improved antennas have good isolation and can suppress mutual signal crosstalk.

[0125] Corresponding to Figure 15B When the four planar antennas 10 are arrayed on the same circuit board and the four improved antennas are arranged in an array with directional radiation directions at equal angles based on the setting of the corresponding electric field isolators 20 that meet the aforementioned requirements, time-division / angle-division / zone detection can be achieved in a 360° spatial range. When performing time-division / angle-division / zone detection, based on the characteristic of the improved antennas to reject electromagnetic radiation in the opposite space, the four improved antennas have good isolation and can suppress signal crosstalk between each other.

[0126] Corresponding to Figure 15C When the four planar antennas 10 are arrayed on the same circuit board, and the array layout of the four improved antennas is formed based on the setting of the corresponding electric field isolators 20 that meet the aforementioned requirements, the directional radiation beams of the four improved antennas have the same overlapping space around a 360° spatial range. Therefore, it can be applied to multi-angle / directional detection scenarios of targets in a segmented / partitioned manner, such as segmented / multi-angle / 360° rotating stereo scanning detection of the human body or limbs.

[0127] It is worth mentioning that when at least two planar antennas 10 are arrayed on the same circuit board and the array layout of the improved antenna is formed based on the setting of the corresponding electric field isolator 20 that meets the aforementioned requirements, each of the improved antennas can be connected by different microwave chips through chip cascading, or they can be driven and detected by the same microwave chip in a time-division / angle-division / zone-division manner.

[0128] It will be understood by those skilled in the art that the above embodiments are merely examples, and features of different embodiments can be combined with each other to obtain implementation methods that are readily conceivable according to the content disclosed in the present invention but are not explicitly shown in the accompanying drawings.

[0129] For example, in some embodiments of the present invention, specifically corresponding to Figure 16A and Figure 16B In this configuration, when at least two planar antennas 10 are arrayed on the same circuit board and the improved antenna array layout is formed based on the setting of the corresponding electric field isolators 20 that meet the aforementioned requirements, on the one hand, the beam deflection angle of the improved antenna can be set / adjusted based on the setting / change of the corresponding structural form of the electric field isolators 20 and / or the setting / change of their position relative to the planar antennas 10; on the other hand, it can also correspond to... Figure 16A and 16B Furthermore, based on the phase difference feeding of each of the planar antennas 10, the beam deflection angle of the improved antenna is set / adjusted.

[0130] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. Improved antenna for lateral directional beam and reverse space denial of planar antennas, characterized in that, The improved antenna comprises: at least one planar antenna, which comprises a reference ground and a planar radiation source arranged in the form of a planar metal layer and spaced apart in parallel with each other, wherein the planar radiation source is arranged to access a feed signal at a position deviating from the physical center point thereof to be fed, and the planar antenna is capable of forming an initial polarization with a polarization direction in the fed state; and an electric field isolator, wherein the electric field isolator is arranged in a conductive material and has a lateral focusing surface, and a three-dimensional coordinate system is established with the physical center point of the planar radiation source as the origin O, the X axis of the three-dimensional coordinate system is established along the polarization direction of the planar antenna on the planar radiation source, and the Y axis of the three-dimensional coordinate system is established on the planar radiation source, and the Z axis of the three-dimensional coordinate system is perpendicular to the planar radiation source, wherein a first spherical surface is defined with the origin O of the three-dimensional coordinate system as the spherical center and a first radius R1 as the radius, a second spherical surface is defined with the origin O of the three-dimensional coordinate system as the spherical center and a second radius R2 greater than R1 as the radius, and a first circular cone is defined with the origin O of the three-dimensional coordinate system as the vertex and the negative Y axis as the axis, wherein the top angle of the section of the first circular cone in the XOY plane is θ1, the space defined by the first spherical surface, the second spherical surface and the inner side surface of the first circular cone is defined as the first space, the lateral focusing surface has a first section intercepted by the first space, and in the state that the bottom surface of the first circular cone is the first section, the bottom surface is capable of independently forming an obstruction to the conical beam with the origin O of the three-dimensional coordinate system as the source point and an angle of 46° inside the first circular cone, wherein the values of R1, R2 and θ1 are set in the range of λ / 8≤R1<R2<3λ / 4 and θ1≥120°, λ is a wavelength parameter corresponding to the frequency of the feed signal accessed by the planar radiation source, so that the improved antenna exhibits a lateral directional radiation characteristic in the radiation pattern, and the lateral direction corresponds to the positive direction of the Y axis of the three-dimensional coordinate system.

2. The improved antenna according to claim 1, wherein the planar antenna is arranged to be fed in a probe feed structure, and the planar radiation source has at least one feed point at which a feed signal is accessed, wherein the feed point deviates from the physical center point of the planar radiation source.

3. The improved antenna according to claim 2, wherein the planar radiation source has only one feed point, and in the state that the planar radiation source is fed by accessing a corresponding feed signal at the feed point, the polarization direction of the planar antenna is the direction of the line connecting the feed point of the planar radiation source to the physical center point of the planar radiation source.

4. The improved antenna of claim 2, wherein said planar radiating source has two said feed points and is fed in a differential feed manner by accessing feed signals with phase difference at the two said feed points, and corresponding to the state that said planar radiating source is fed, the polarization direction of said planar antenna is the direction parallel to the line connecting the physical center point of said planar radiating source and the two said feed points.

5. The improved antenna of claim 2, wherein said planar radiating source has two said feed points and is fed by accessing feed signals with same phase at the two said feed points, and corresponding to the state that said planar radiating source is fed, the polarization direction of said planar antenna is the direction connecting the midpoint of the line segment connecting the two said feed points and the physical center point of said planar radiating source.

6. The improved antenna of claim 1, wherein said planar radiating source is arranged to be fed in a microstrip feed structure, corresponding to said planar radiating source being fed by at least one microstrip line connected thereto.

7. The improved antenna of claim 6, wherein said planar radiating source is fed at a single feed position, corresponding to said planar radiating source being fed by a single said microstrip line, and wherein corresponding to the state that said planar radiating source is fed, the polarization direction of said planar antenna is the direction connecting the position of said planar radiating source connected to said microstrip line and the physical center point of said planar radiating source.

8. The improved antenna of claim 1, wherein said planar radiating source is arranged to be fed in an edge feed structure, corresponding to said planar radiating source being fed by at least one edge feed line coupled thereto.

9. The improved antenna of claim 8, wherein said planar radiating source is fed at a single feed position, corresponding to said planar radiating source being fed by a single said edge feed line coupled thereto, and wherein corresponding to the state that said planar radiating source is fed, the polarization direction of said planar antenna is the direction connecting the center position of said edge feed line and the physical center point of said planar radiating source.

10. The improved antenna of claim 1, wherein said planar radiating source is arranged to be recessed in a non-polarization direction, so that the strength of the electric reactance field generated by the coupling of said planar radiating source based on itself can be improved, thereby improving the radiation gain of said improved antenna in the lateral directional radiation direction.

11. The improved antenna of claim 1, wherein the positional relationship between said electric field isolator and said planar antenna is arranged to be adjustable.

12. The improved antenna of claim 1, wherein said electric field isolator is arranged in a split body form, so that the form adjustment of said electric field isolator can be formed based on the activity between the respective split bodies.

13. The improved antenna of any one of claims 1 to 12, wherein R1 = λ / 4, R2 = λ / 2, and θ1 = 120°.

14. The improved antenna of claim 13, wherein at least two said planar antennas are arranged in an array on the same circuit board, and based on the arrangement of a corresponding number of said electric field isolators, an array layout of said improved antenna is formed.

15. The improved antenna of claim 13, wherein the planar antenna has a primary directional radiation direction with the reference ground facing the planar radiation source direction, and at least two of the planar antennas are arranged back-to-back with their primary directional radiation directions facing away from each other.

16. The improved antenna of claim 15, wherein the two back-to-back arranged planar antennas share a common reference ground, and the two planar radiation sources are arranged back-to-back with the common reference ground in between.

17. The improved antenna of claim 13, wherein a second cone is defined with the origin O of the three-dimensional coordinate system as its apex and with the positive Y-axis as its axis, and wherein the second cone has a top angle θ2 of its cross-section in the XOY plane satisfying θ2≥120°, and wherein the second space is defined by the first sphere, the second sphere, and the outer surface of the second cone, and wherein the electric field isolator is located in the second space.

18. The improved antenna of claim 17, wherein the electric field isolator further has a reverse rejection surface opposite to the lateral focusing surface, and wherein the reverse rejection surface has a second cross-section intercepted by the first space, and wherein the second cross-section is capable of independently forming a barrier to a cone-shaped light beam with an angle of 46° and with the origin O of the three-dimensional coordinate system as its source point inside the first cone.

19. The improved antenna of claim 13, wherein the electric field isolator further has at least one annular slot to form at least one level of choke to suppress the radiation energy of the improved antenna in the backward space based on the arrangement of the annular slot.

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